Re: P0174 on a 04 Deville

Remember - the rear caliper pistons do NOT compress back into the caliper - they must be screwed back in and the piston face indents aligned with the pad backing plate indents. It's part of the parking brake ratchet adjustment mechanism.

You will need the proper torque values for the rear brake parts bolts. Brake pin lube.

Re: P0174 on a 04 Deville

Yes, I think I have done my research and found a tool called "brake cube" at Harbor Freight for $4. I have also updated my torque wrenches to providing much higher setting for the 100 ft/lbs for properly attaching the wheels. One concerns remains though: he had a leaking master cylinder and it was replaced. We have bought OE brake fluid according to DOT-3 specifications from ACDelco but I am slightly concerned about DOT-3 being deprecated. Is there a safe way to determine whether the shop switching the master cylinder had used DOT-3 or its successor?

Re: sporadic SES light and exotic codes

Originally Posted by Ranger

I'm pretty sure that there is only one CC cable and I only see one in that picture.

Little update: After 5 minutes intensive search, I found the cable bundle and a broken connector under the air filter housing. CC codes went right away. Unfortunately, I had much less luck with the brakes. After disassembling just the RL, I realised that the ACDelco 14D792CH Advantage Rear Ceramic Disc Brake Pad Set does not fit a DTS. Strange, as those have been advertised for code JL9 and shown as exact fit.

Anyway, the old pads still have some life on them and the car is braking so much better now. Makes one wonder how much difference a good cleaning and proper lubrication of the caliper slide pins can make.

Re: sporadic SES light and exotic codes

Update:

1. The CC is working again after simply re-attaching the cable/wire bundle.

2. We addressed the rear brakes, changed all pads and rotors. IMHO the mechanic overstated the wear on the brakes quite a bit, since rotors and pads have had half their life on it. Anyway, the new pads produce significantly less dust, so that is a plus. However, after putting all back together and rotating the wheels at the same time, we were puzzled on how we check the proper performance of the replaced parts. The car brakes just as it did before - like a tank Compared to the braking capabilities of my Audi, I sometimes get panic attacks. Anyway, I guess the 1.2 tons weight difference do contribute to that feeling. We thought using the parking break would be a good test, it keeps the car in place on a hill but the car starts turtles away when put in drive. I personally would think that's not too much of an issue since my wifes beetle (manual) had many episodes of her forgetting the parking brake until a "funny smell" happened.

Is there any way to check that apart from bringing it to a mechanic?

3. The sporadic SES light is back. He was able to isolate them occurring at prolonged highway speed cruising. I took the car for a trip to the country I was planning anyway and, voila, probably 30 minutes into the trip at 75 mph and very smooth cruising SES came on. I stopped to see two old "friends" saying hello:

P0171 H - System too Lean (Bank 1)
P0174 H - System too Lean (Bank 2)

Funny thing is, at longer drives, the SES light goes OFF as well. The car was on a drive to Galveston with the light on at first and arrived there with SES off. I get another bottle of spray and check the plenum area again just in case I have overlooked something at the first time. I am, maybe wrongly, very hesitant to change the plenum (because of the intake gaskets and everything) if this is not the major reason (The earlier repair with the PCV hose did wonders so far, even the MPG's jumped from below 13 to 18).

EDIT: It took so long because Amazon send me the wrong pads - I took one old pad and walked into an Advanced to find out the correct part number. i was lucky, a customer returned compatible pads but did not put the springs back in the pack. Got a set of 4 Wearever Ceramic pads for $15 and just recycled (cleaned and made sure they were "springy" enough) the installed springs. The ACDelco Advantage rotors fit perfectly.

Re: sporadic SES light and exotic codes

I've had an opportunity to check the wheel temperature: after a normal drive the wheels are quite cool, after 40m stop-and-go the wheels are warm but nothing resembling "very hot". We'll check the plenum area with some aerosol today.

I have two more questions, though:

1. When the caddy is stopped or going quite slow a subsequent acceleration is a gurgling/sucking liquid displacement sound coming from the engine compartment. What is that?
2. The transmission fluid condition display is now down to 50%. Is this something he's to worry about?

Re: sporadic SES light and exotic codes

Originally Posted by Ranger

Trans fluid life monitor almost always stays at 99 - 100%. The only thing that decrements it is overheating the trans. I'd change the trans fluid.

I have not had the time to check the plenum yet but I was discussing (and researching) the transmission fluid change. Here on the board there seems to be an opinion that it needs to be done personally to make sure it's done right and that the mechanic is not damaging the systems by force flushing it. So I guess one of those $49.99 trasmission fluid changes is out of the question?

If I may trouble you with another question: the Deville's computer sees to suffer from amnesia since a couple of days. I got a call three days ago that the MPG display reset itself to 0.0 for no apparent reason. It continues to do so several times a day right after the car is started. Battery power is ok and all other systems work perfectly. Is this and indicator for yet another big(-er) issue?